(1) Field of the Invention
The present invention is directed generally to transducer and more specifically to a compact multi-layered transducer capable of withstanding hydrostatic pressures in the order of 9,000 pounds per square inch (psi) particularly for sub-ocean bottom imaging applications.
(2) Description of the Prior Art
Conventional sub-bottom profiling systems rely on relatively low frequency transducers in the order of 3.5 kHz transducers to penetrate and explore the oceans' sediments. However, necessity dictates that these transducers need to be small enough to fit on their intended platforms (such as towed underwater vehicles, tethered bodies, and the like). As a result of their small size compared to the required acoustic wavelength, they provide little to no acoustic directionality, and their lateral spatial resolution is poor.
Background information in this field is provided in the following references, each of which is incorporated in their entirety: P. J. Westervelt, “Parametric Acoustic Array,” J. Acoust. Soc. Am. 35, p. 535 (1963); C. H. Sherman and J. L. Butler, “Transducers and Arrays for Underwater Sound” (Springer, New York, 2007) (See page 156); L. E. Kinsler and A. R. Frey, “Fundamentals of Acoustics” (John Wiley and Sons, New York, 1962) (See page 141); U.S. Pat. No. 6,255,761 to Benjamin, “Shaped piezoelectric composite transducer and method of making.”
In response to a need to explore the ocean sub-bottom from small autonomous vehicles and other platforms, there is a need for a low cost scalable piezocomposite-based multi-layer parametric mode transducer that overcomes the above and other shortcomings of the prior art.